Prevent possible infinite recursion in ViewProperties

If each directory can have its own view properties, and loadting the
.directory file fails in a directory, we have to load the global view
properties. However, if we try to do this by changing the "global view
properties setting" and loading the view properties for the same
directory again, we might get an infinite recursion if changing the
setting fails.

We now force a loading of the global view properties by constructing a
new ViewProperties object with an empty URL.

Thanks to Kurt Hindenburg for helping to debug this issue (which was
only reproducible on MacOS).


FIXED-IN: 4.10.5
REVIEW: 111182